Vibration tumbler / polishers any one?

I don't know if any of you makers use them? But I'm doing a little project of mine and cleaning up a antique leather working splitter. Any way I want to make the thing look new...no better then new again. I want to polish a bunch of little mettle (iron,steel, and bronze) pieces. I did some reading on line and it seems s a vibration tumbler is the way to go? Any one here have some input or tips for me? Can a mirror polish be achieved with one ? I was thinking corncob media mixed with green chrome powder would do a good job?

I use walnut media loaded with rubbing compound, say Turtle wax,then corn cob media with polishing compound or 1micron Diamond paste.
The finish is very bright. If you want full mirror you need to get rid of all scratches first, and then tumble for a few days in each media.